An institutional experience of a rare diagnosis of subcutaneous panniculitis-like T-cell lymphoma.

Abstract

e19073 Background: Subcutaneous Panniculitis-like T-cell lymphoma (SPTCL) is a rare diagnosis making up < 1% of Non-Hodgkin lymphomas. Data from Surveillance Epidemiology and End Results (SEER) identified a total of 204 cases from 2000-2020. Clinically, SPTCL presents as subcutaneous nodules and is difficult to distinguish from other more common conditions such as lupus erythematosus panniculitis. Most of our understanding on presentation, diagnosis and treatment on SPTCL is limited to small case series. Methods: Following IRB approval, a multi-center retrospective clinical and pathological review identified patients diagnosed with SPTCL from 1/1/2013-10/24/23. The study was conducted at Baylor Scott & White system (CTX). Inclusion criteria included ≥ 18 years old, SPTCL AB sub-type. Patients were seen for > 2 visits during time of active treatment. Cases of SPTCL y8 sub-type were excluded from the study. A descriptive analysis of the clinical presentation, treatment choice/duration, and clinical outcomes was generated. Results: A total of 5 patients met criteria for inclusion during the previously defined time period. The median age at diagnosis was 39 with a median follow up of 6 years. Patients presented with multiple nodular lesions affecting the chest, trunk, axilla, arms, and legs. Sixty percent of patients received misdiagnosis and experienced delay in appropriate treatment with a maximum delay of 10 years. Histopathology showed panniculitis-like lymphoid infiltrate composed predominantly of T lymphocytes, with areas of adipocyte rimming and a background of fat necrosis. No patients developed hemophagocytic syndrome. Patients were treated with steroids alone or in combination with cyclosporine, methotrexate, and/or romdespin. Sixty percent of patients achieved a complete response, and 40% remain in remission. The 5-year disease specific survival rate was 100%. Conclusions: SPTCL showed an indolent course in the patient population studied. All patients treated with systemic steroids as first line therapy responded favorably. When tolerated cyclosporine and methotrexate controlled disease in patients that showed progression following the completion of steroid taper.